During the seven month period between the third quarter of 2008 and the first quarter of 2009, nearly 700,000 American workers lost their jobs-on a monthly basis (Greenstone and Looney 2011). The Great Recession began in the United States in December of 2007, but blossomed into a global recession by 2009 (IMF 2009). Unlike previous recessions, which were marked by sharp declines in employment, The Great Recession (TGR) was coupled with a housing crisis of unprecedented scale (Ellen and Dastrup 2012) that predated (2006) the employment losses. Although The Great Recession (TGR) officially ended in 2009, positive job growth didn't return until the Spring of 2010 and housing prices did not begin to rebound until 2012. The effects of TGR continue to ripple throughout the United States, leaving our socio-economic landscape changed in significant ways. This exploratory proposal seeks to study a contemporaneous measure of population health-birthweight-and how it might have been affected by TGR. We will develop two unique sets of data that can be used in future studies of population health and health disparities. We also overcome many of the limitations in prior studies of recession and health, which we outline in our innovation section. Ultimately, our study will develop a model for assessing the effect of other dramatic social events on population health and health disparities by using geo-coded vital statistics data. Aim 1. To assess the level of childbirth selectivity during pre-recessionary, recessionary and post-recessionary periods Aim 2. To explore the impact of the great recession on birth outcome disparities Aim 3. To compare the effects of recession indicators on birth outcomes among mothers giving birth during non- recessionary and recessionary periods Our project will produce a data set with wide usability for studying the effects of recession at more precise geographies than previously possible; further, we will provide direct estimates of the total effect of recession on population infant health and its effect on birth outcome disparities. Our recession indicators database, and our code for producing sibling groups in birth certificate data will be made available to researchers for further study.